#include <stdio.h>
main()/*这是用来求累加的程序，对应可执行文件‘1-1’ */
{
int i , in , out=0;
printf(" input the number you wanna add up \n");
scanf("%d",&in);
for(i=1;i<=in;i++)
out=out+i;
printf("\n");
printf("the outcome is :%d\t",out);
}


